Cancer continues to be a major health problem in the United States and world-wide. In 2014, in the United States, there are expected to be more than 1.5 million new cancer cases and more than 580,000 cancer deaths. Cancer-related deaths account for nearly ¼ of all deaths in the U.S. Most common childhood cancers are leukemias, lymphomas, brain tumors, and bone cancer, while adult cancers are more likely to be lung, colon, breast, prostate, and pancreas. Although enhanced early-stage tumor diagnosis and management have significantly increased patient survival, development and discovery of new anticancer therapies are still needed, in part because some patients exhibit insensitivity to current anticancer drugs or develop drug-resistance after a period of treatment.
Leukemia is one of the most common hematologic malignancies in humans which usually begins in the bone marrow and results in high numbers of abnormal white blood cells. Among acute leukemia, acute lymphoblastic leukemia (ALL) is a predominant cause of childhood leukemia, while acute myeloid leukemia (AML) represents about 90% of all adult leukemia and the second most common pediatric leukemia. While imatinib has improved therapy of chronic myelogenic leukemia due to specificity to its target the bcr-abl fusion gene product, the current treatment of ALL and AML includes cells proliferation affecting drugs that are not selective for hematologic malignancies, such as vincristine, anthracycline, cyclophosphamide etc. Such treatments often lead to severe side effects, development of resistance, and low survival rates.